I start rugging at night (she's out at night til October time, when she gets turned around) well before I clip. I will clip her out probably late Oct time, when she is fluffy enough to get sweaty - esp if I take her cubbing/hunting. I don't like her to drop condition too much going into winter so I would turn out in a LW rug if the evenings get any chillier or are very wet.
when the horse needs it and if the horse needs it for example my old lad is starting to get his winter coat now so i shall clip him as soon as its through because he will get hot and sweaty other wise and i will rug him if the weather demands it.
4 to 6 weeks after the last clip! My lad is fully clipped and hogged year round because he competes as well. He's not rugged yet - but it is getting very close to it at night at the moment. Come winter I'm afraid he is rugged in various combinations 24/7.
Children's hunt in in 2 weeks (Yay!) so we'll need to clip before that so my daughter can look up to the mark there.